This invention relates generally to an anti-allergy treatment and more specifically to such treatment using effective amounts of 2-(substituted amino)-4,5-dihydro-4-oxo-3-furancarboxylic acids and derivatives thereof.
A number of 2-(substituted amino)-4,5-dihydro-4-oxo-3-furancarboxylic acids and their esters and amides have been previously prepared (Capuano, L. et al., Chem. Ber., 109, pp 212-217 (1976); Mulholland, T. P. C. et al., J. Chem. Soc., Perkins Trans I, pp 1225-1231); and Ibrahim, N. S. et al., Z. Naturforsch., 40B, pp 129-131, (Mar. 1985). No biological activity for the latter compounds is reported. We have found that these compounds as well as other similarly prepared derivatives are useful as anti-allergic agents.
Hay fever, perennial allergic rhinitis and bronchial asthma all can result from the inhalation of specific antigenic materials in susceptible individuals. The interaction of the allergen with mast cells leads to the release of a variety of vasoactive, chemotactic and enzymatic mediators which are presumed to be responsible for the vasodilation, edema, increased mucous secretion and other symptomatology that are characteristic of these diseases. Administration of the furanone compounds of the invention led to inhibition of the allergic mediator release. Although the mechanism by which the compounds function is not absolutely known, applicants have found that the furanones are active in vivo in the Rat Active Anaphylaxis Model and inhibit mediator release from sensitized rat mast cells. They also inhibit wheal formation and flare reactions produced in rats by the intradermal injection of the allergic mediators histamine, serotonin or bradykinin.